A noise reduction circuit for a matrix LED driver includes a pseudo random number generator, an up counter, a clock module, and a plurality of matrix switch controllers. The matrix switch controllers and the up counter randomly change a power-on sequence applied across matrix switches in the matrix LED driver according to working random numbers generated by the pseudo random number generator. The circuit prevents jitter-induced noise from periodically reoccurring at the power source of the matrix LED driver, thereby reducing noise energy.

A noise reduction circuit for a matrix LED driver includes a pseudo random number generator, an up counter, a clock module, and a plurality of matrix switch controllers. The matrix switch controllers and the up counter randomly change a power-on sequence applied across matrix switches in the matrix LED driver according to working random numbers generated by the pseudo random number generator. The circuit prevents jitter-induced noise from periodically reoccurring at the power source of the matrix LED driver, thereby reducing noise energy.

The invention relates to an isolated driver (100) for lighting means (109), comprising: a primary circuit (100a), a secondary circuit (100b), an isolation barrier (106) separating the primary circuit (100a) and the secondary circuit (100b), wherein a ground potential of the primary circuit (100a) and a ground potential of the secondary circuit (100b) are connected via a capacitor (107), and a control circuit (111) on the secondary side (100b), monitoring a current to/from the capacitor (107) to the ground potential of the secondary circuit (100b) and issuing a mains (101) failure signal in case the current does not meet predefined conditions, preferably in case no such current is detected.

The invention relates to an isolated driver (100) for lighting means (109), comprising: a primary circuit (100a), a secondary circuit (100b), an isolation barrier (106) separating the primary circuit (100a) and the secondary circuit (100b), wherein a ground potential of the primary circuit (100a) and a ground potential of the secondary circuit (100b) are connected via a capacitor (107), and a control circuit (111) on the secondary side (100b), monitoring a current to/from the capacitor (107) to the ground potential of the secondary circuit (100b) and issuing a mains (101) failure signal in case the current does not meet predefined conditions, preferably in case no such current is detected.

A lighting system includes a light engine including a correlated color temperature (CCT) terminal configured to transmit a first power signal having a first variance and to receive a CCT signal, the light engine being configured to emit light according to the CCT signal, and a CCT clamp coupled to the CCT terminal, and configured to receive the first power signal and to generate the CCT signal having a second variance, the first variance of the first power signal being greater than the second variance of the CCT signal.

The present disclosure provides a power factor improvement circuit with a DC/DC converter including an arithmetic circuit. A first voltage having a full-wave rectified waveform is received by an input voltage detection terminal of the power factor improvement circuit. A second voltage is generated by amplifying an error between a first detection voltage and a reference voltage according to an output voltage of the DC/DC converter. A third voltage is generated by multiplying the first voltage by the second voltage. The arithmetic circuit adds an offset voltage to a third voltage to generate a fourth voltage. A comparator is configured to compare a second detection voltage with the fourth voltage. A drive circuit is configured to turn on/off drive of the switching transistor according to an output of the comparator. When the second detection voltage is higher than the fourth voltage, the switching transistor is turned off.

An LED tube lamp comprises: a glass lamp tube; a light diffusion layer disposed on a surface of the glass lamp tube; an LED light strip, which comprises a fixing portion and an extending portion disposed in the glass lamp tube; a plurality of LED light sources mounted on the fixing portion of the LED light strip; a fixing structure disposed between the fixing portion and the inner circumferential surface the glass lamp tube; a power supply module disposed on the fixing structure and electrically connecting to the LED light strip and two end caps attached to two ends of the glass lamp tube respectively. The fixing structure comprises a first end fixedly connected to the inner circumferential surface of the glass lamp tube and a second end fixedly connected to the fixing portion of the LED light strip and not connected to the extending portion of the LED light strip.

An LED tube lamp comprises: a glass lamp tube; a light diffusion layer disposed on a surface of the glass lamp tube; an LED light strip, which comprises a fixing portion and an extending portion disposed in the glass lamp tube; a plurality of LED light sources mounted on the fixing portion of the LED light strip; a fixing structure disposed between the fixing portion and the inner circumferential surface the glass lamp tube; a power supply module disposed on the fixing structure and electrically connecting to the LED light strip and two end caps attached to two ends of the glass lamp tube respectively. The fixing structure comprises a first end fixedly connected to the inner circumferential surface of the glass lamp tube and a second end fixedly connected to the fixing portion of the LED light strip and not connected to the extending portion of the LED light strip.

A light-emitting diode (LED) lighting device driver with improved luminous performance is provided, which includes a driving circuit and a current ripple reduction circuit. The driving circuit outputs a driving current. The current ripple reduction circuit receives the driving current and reduces the current ripple of the driving current to generate an output current in order to drive a light-emitting module. The current ripple reduction can effectively depress the current ripple of the driving current outputted from the driving circuit in order to generate the output current and then drive the light-emitting module by the output current. Thus, the luminous performance of the light-emitting module can be significantly improved with a view to achieve energy saving and conform to environmental protection requirements.

A light-emitting diode (LED) lighting device driver with improved luminous performance is provided, which includes a driving circuit and a current ripple reduction circuit. The driving circuit outputs a driving current. The current ripple reduction circuit receives the driving current and reduces the current ripple of the driving current to generate an output current in order to drive a light-emitting module. The current ripple reduction can effectively depress the current ripple of the driving current outputted from the driving circuit in order to generate the output current and then drive the light-emitting module by the output current. Thus, the luminous performance of the light-emitting module can be significantly improved with a view to achieve energy saving and conform to environmental protection requirements.